System, apparatus and method for concurrent reception of multiple channels spaced physically in radio frequency spectrum

ABSTRACT

In one embodiment an apparatus includes: a mixer to downconvert a radio frequency (RF) spectrum including at least a first RF signal of a first channel of interest and a second RF signal of a second channel of interest to at least a first second frequency signal and a second second frequency signal; a first digitizer to digitize the first second frequency signal to a first digitized signal, the first digitizer configured to operate as a low-pass analog-to-digital converter (ADC); a second digitizer to digitize the second second frequency signal to a second digitized signal, the second digitizer configured to operate as a band-pass ADC; and a digital processor to digitally process the first digitized signal and the second digitized signal.

The present application is a continuation of U.S. patent applicationSer. No. 17/087,911, filed on Nov. 3, 2020, which is a continuation ofU.S. patent application Ser. No. 16/225,562, filed on Dec. 19, 2018, nowU.S. Pat. No. 10,833,711, issued on Nov. 10, 2020, the content of whichis hereby incorporated by reference.

BACKGROUND

With the ever increasing connectedness of many types of devices coupledtogether in different network architectures, wireless receivers arebeing incorporated into a variety of device types. Many of these devicesare small battery-powered devices, and the power consumption of wirelesscommunication can be a significant driver of battery wear. To this end,many devices implement techniques to operate in low power modes when notbeing used. Nevertheless, increased emphasis is being placed onproviding wireless communication with reduced power consumption.

Certain wireless devices implement multiple wireless receivers so thatthey can communicate on physically spaced channels. However, havingmultiple receivers adversely increases power consumption.

SUMMARY OF THE INVENTION

In one aspect, an apparatus includes: a low noise amplifier (LNA) toreceive and amplify a radio frequency (RF) spectrum including at least afirst RF signal of a first channel of interest and a second RF signal ofa second channel of interest; a mixer to downconvert the first RF signalto a first second frequency signal and to downconvert the second RFsignal to a second second frequency signal; a first digitizer todigitize the first second frequency signal to a first digitized signal,the first digitizer configured to operate as a low-passanalog-to-digital converter (ADC); a second digitizer to digitize thesecond second frequency signal to a second digitized signal, the seconddigitizer configured to operate as a band-pass ADC; and a digitalprocessor to digitally process the first digitized signal and the seconddigitized signal.

In an example, the apparatus further comprises a controller to configurea local oscillator to generate a mixing signal having a frequencybetween a frequency of the first channel of interest and a frequency ofthe second channel of interest. The mixer may be a complex mixer todownconvert the first RF signal to positive and negative first secondfrequency signals and downconvert the second RF signal to positive andnegative second second frequency signals. The controller may beconfigured: for a first time period, to configure the second ADC tooperate at a first center frequency to digitize and pass the secondchannel of interest; and for a second time period, to configure thesecond ADC to operate at a second center frequency to digitize and passa third channel of interest.

In an example, the controller may dynamically control a center frequencyfor the second ADC to perform frequency hopping for a plurality ofchannels of interest. The apparatus may further include a low-passfilter coupled between the mixer and the first and second digitizers.The controller may configure the low-pass filter to operate at pluralityof cutoff frequencies, each of the plurality of cutoff frequenciesassociated with a corresponding center frequency for the seconddigitizer. The controller may cause the second digitizer to be poweredoff when the apparatus is in operation in a low power mode. The firstdigitizer may digitize information of the first channel of interest,where the first channel of interest is a fixed channel and the frequencyof the mixing signal is to be fixed. In an example the first and seconddigitizers may be delta-sigma converters. The first and seconddigitizers also may be configured as complex ADCs.

In another aspect, a method includes: configuring, via a controller, afirst ADC of a receiver to operate at a low-pass to capture a firstchannel of interest; configuring, via the controller, a second ADC ofthe receiver to operate at a band-pass to capture a second channel ofinterest; receiving, in a common receiver signal processing path of thereceiver, a RF spectrum, downconverting the RF spectrum to anintermediate frequency (IF) spectrum including the first channel ofinterest and the second channel of interest, and providing the IFspectrum from the common receiver signal processing path to the firstADC and the second ADC; in the first ADC, digitizing the first channelof interest into a first digitized signal and providing the firstdigitized signal to at least one digital processor; and in the secondADC, digitizing the second channel of interest into a second digitizedsignal and providing the second digitized signal to the at least onedigital processor.

In an example, the method further comprises re-configuring, via thecontroller, the second ADC to operate at a second band-pass to capture athird channel of interest. The method may further comprise: configuringa low-pass filter of the common receiver signal processing path tooperate at a first cutoff frequency to enable the second channel ofinterest to be passed; and re-configuring the low-pass filter to operatea second cutoff frequency to enable the third channel of interest to bepassed. The method may further comprise re-configuring the low-passfilter and the second ADC according to a predetermined schedule toenable frequency hopping for a plurality of channels of interest. Themethod may further comprise: causing the second ADC to enter into a lowpower mode; detecting a beam signal via the first ADC; and in responseto the beam signal, causing the second ADC to exit the low power mode toenable the second ADC to digitize the second channel of interest.

In yet another aspect, a system includes: a first internet of things(IoT) device to perform one or more functions. The first IoT device mayinclude: a common receiver signal processing path having a LNA toreceive and amplify a RF spectrum including at least a first RF signalof a first channel of interest and a second RF signal of a secondchannel of interest, and a mixer to downconvert the first RF signal to afirst IF signal and to downconvert the second RF signal to a second IFsignal; a first ADC coupled to the common receiver signal processingpath to digitize the first IF signal to a first digitized signal, thefirst ADC configured to operate at a low-pass; a second ADC coupled tothe common receiver signal processing path to digitize the second IFsignal to a second digitized signal, the second ADC configured tooperate at a controllable band-pass; and a digital processor todigitally process the first digitized signal and the second digitizedsignal. The system may further include a plurality of devices coupled tothe first IoT device, where at least one of the plurality of devicescomprises a control device to communicate with the first IoT device viaat least another one of the plurality of devices.

In an example the first IoT device further comprises a controller toconfigure a local oscillator to generate a mixing signal having afrequency between a frequency of the first channel of interest and afrequency of the second channel of interest. The controller may beconfigured to dynamically control a center frequency for the second ADCto perform frequency hopping for a plurality of channels of interest,where the controller is to cause the second ADC to operate for a firsttime period at a first center frequency to digitize and pass the secondchannel of interest and to operate for a second time period at a secondcenter frequency to digitize and pass a third channel of interest.

The common receiver signal processing path may include a low-passfilter, and the controller is to configure the low-pass filter tooperate at plurality of cutoff frequencies, each of the plurality ofcutoff frequencies associated with a corresponding center frequency atwhich the second ADC is to operate. The controller may also cause thesecond ADC to enter into a low power mode, and in response to a beamsignal received from the control device, cause the second ADC to exitthe low power mode to enable the second ADC to digitize and pass thesecond channel of interest.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a receiver in accordance with oneembodiment.

FIG. 2 is a flow diagram of a method in accordance with an embodiment.

FIG. 3 is a flow diagram of a method in accordance with anotherembodiment.

FIGS. 4A and 4B are illustrations of RF and IF frequency spectrums inaccordance with an embodiment.

FIG. 5 is a block diagram of an example integrated circuit in accordancewith an embodiment.

FIG. 6 is a block diagram of mesh network in accordance with anembodiment.

DETAILED DESCRIPTION

In various embodiments, a receiver for incorporation into many differentdevice types including battery-operated low power devices may beimplemented with a common front end signal processing path to performanalog signal processing operations on a received radio frequency (RF)spectrum. After downconversion and potentially additional processing inthis common front end receiver signal processing path, the downconvertedsignal spectrum is provided to multiple back end signal processing pathsincluding multiple independent digitizers, which may be differentlyconfigured and controlled to a given one of multiple channels ofinterest concurrently. Thereafter additional back end processingcircuitry such as digital signal processing circuitry may furtherprocess the digitized signals, including performing demodulation andpotentially other signal processing operations.

In this way, embodiments enable a receiver architecture with reducedchip real estate and lower power consumption, owing to the presence of asingle front end receiver signal processing path. In addition, powerconsumption may be further reduced by dynamically causing one or more ofthe multiple backend receiver signal processing paths (includingcorresponding digitizers) to be disabled or otherwise placed in a lowpower mode, when a receiver does not need to concurrently receive andprocess multiple channels of interest. While embodiments are describedherein in the context of integrated circuit (IC)-based receivers thatare implemented within small devices such as internet of things (IoT)devices, understand that embodiments herein may be implemented in othertypes of devices and receiver architectures.

Referring now to FIG. 1, shown is a block diagram of a receiver inaccordance with one embodiment. As shown in FIG. 1, receiver 100 is aradio receiver, which may be implemented in a given integrated circuit,such as a given IoT device. In embodiments, receiver 100 may beimplemented on a single semiconductor die and integrated in anintegrated circuit (IC) package. With a configuration as in FIG. 1, acommon front end signal processing path is in turn coupled to multipleback end signal processing paths to enable concurrent reception ofmultiple channels that are spaced physically apart in an RF spectrum.

As illustrated, receiver 100 is coupled to receive incoming RF signalsfrom an antenna 105. Note that antenna 105 may be external from theIC/semiconductor device, in many cases. In any event, RF signalsreceived via antenna 105 are provided to a low noise amplifier (LNA)110. In embodiments, LNA 110 may provide a controllable amount gain tothe RF signals, e.g., approximately 20 decibels (dB) of gain. Althoughembodiments may vary, in an implementation for a Z-Wave communicationprotocol, these incoming signals may be received at one or more RFfrequencies of between 800 megahertz (MHz) and 1 gigahertz (GHz).

The amplified RF signals may be provided in turn from LNA 110 to a mixer120, which operates to downconvert the RF spectrum to a lower frequency,e.g., one or more given intermediate frequency (IF) signals. Eachchannel has its own modulated carrier. When the received RF signalincludes multiple, concurrently active channels, then the downconvertedresult includes equally many non-overlapping IF bands, each centeredaround the respective downconverted carrier. Distinct RF carrierscontribute distinct IF frequencies. In effect, the resulting IF signalis the sum of multiple IF signal, one for each channel. To this end,mixer 120 receives a local oscillator frequency (F_(LO)) as generated ina local oscillator, such as a frequency synthesizer 170 (and which alsomay be adapted on the same semiconductor die as the rest of receiver100). As described herein, embodiments may be used to control the LOfrequency based at least in part on one or more channels of interestwithin the RF spectrum. In embodiments herein, this LO frequency may bein the range of between approximately 800 and 1000 MHz.

Still with reference to FIG. 1, the downconverted IF signal sources areprovided to a low-pass filter (LPF) 130, which may perform a low-passfunction on the IF signals to pass signals in a range between 0-5.5 MHz.As illustrated in FIG. 1, LPF 130 may (in slightly more compleximplementations) split the band into two or more sub-bands, e.g., oneband covering the lower end (LP) and the other band covering the upperpart, or a fraction of the upper part (BP). As will be described herein,the cutoff frequency (or frequencies) of LPF 130 may be controlled basedat least in part on one or more channels of interest within the IFspectrum, to ensure that they pass through LPF 130 to further portionsof the signal processing path. In embodiments, the gain through thesingle or multiple LPF paths is controllable and controlled by an AGCsubsystem (e.g., implemented in a controller 180). While theseparticular components discussed above are present in this example commonsignal processing path, additional or different components may bepresent in other embodiments.

In turn, gain controlled IF signals are provided to multiple parallelsignal processing paths including analog-to-digital converters (ADCs)150 ₀-150 ₁. Understand while only two ADCs are shown for ease ofillustration, in some embodiments more than two parallel processingpaths including ADCs may be present. In the embodiment shown, ADC 150 ₀may be configured as a low-pass ADC having a bandwidth of approximately0.5 MHz and centered near 250 kHz. In embodiments, ADC 150 o may beconfigured to process a channel that does not move in frequency and isto be available all the time.

In turn, ADC 150 ₁ may be implemented as a band-pass ADC having acontrollable center frequency and a bandwidth of approximately 0.5 MHz.Depending upon a selected channel of interest, in one embodiment ADC 150₁ may be dynamically controlled to have center frequencies of 1, 2 or 4MHz. Of course other example center frequencies are possible in otherembodiments. ADC 150 ₁, with a changing center frequency and/or imagesetting, thus may be used to receive different channels.

In one embodiment the maximum center frequency for band-pass ADC 150 ₁may be set at or exceeding 4 MHz, in order to cover a given frequencydifference in channels to be processed. The flexibility in setting thechannels and the bandwidth of ADC 150 ₁ may depend on the required stepsand coverage of the channels. A system with center frequencies in theset of 1, 2, 3 and 4 MHz and a bandwidth of (just over) 1 MHz wouldallow coverage of any placement of a fourth channel. A narrowerbandwidth of 0.5 MHz would double the oversampling ratio (OSR). A morerestricted set of center frequencies such as 1, 2 and 4 MHz may simplifyanalog circuits at the cost of having less than complete coverage in thecase of deployments having large frequency spans.

Assuming a 175 kHz spacing between ADC 150 ₁ edge and carrier, and 325kHz low IF for 100 kbps modulation, possible carrier frequencydifferences for 1 MHz and 0.5 MHz bandwidths and stepping the band-passcenter frequency to 1, 2 and 4 MHz are shown in Table 1 below. Table 1assumes that the image setting for the low-pass receive path can be setarbitrarily. In a given deployment a fourth channel may be fixed in onepart of the low-pass input range (high or low image), and then thepossible ranges for the remaining carrier frequencies are obtained bychanging both center frequency and image setting for the band-pass ADC(using total bandwidth for the band-pass ADC, and half bandwidth for thelow-pass ADC).

TABLE 1 b/w F_(BP) = 1 F_(BP) = 2 F_(BP) = 4 1 [0.35; 2.65] [3.35; 4.65]0.5 [0.6; 2.4] [1.6; 2.4] [3.6; 4.4]

During operation, ADC 150 ₁ may be dynamically controlled to operate atthese different center frequencies to detect the presence of incomingsignals of different channels, e.g., as transmitted by different devicesin a network architecture. To this end, controller 180 is provided tocontrol bandwidth and center frequency of ADC 150 ₁ (and also to controla cutoff frequency for ADC 150 ₀). Controller 180 further may beconfigured to control the LO frequency of the mixing signal output fromfrequency synthesizer 170 and also to control the cutoff frequency forLPF 130, as described herein. In embodiments, controller 180 may beimplemented in hardware such as a microcontroller or so forth thatexecutes instructions stored in a non-transitory storage medium such asa firmware storage, flash memory or so forth. Understand that controller180 may perform further control functions for other components ofreceiver 100.

With further reference to FIG. 1, the digitized signals output from ADCs150 _(0, 1) are provided to a digital processor 160. In differentimplementations, digital processor 160 may be a single digital signalprocessor (DSP) that concurrently receives and processes these multipledigitized signal streams. In other cases, separate digital processorsmay be provided to handle each of the digitized signal streams. In somecases, digital processor 160, which demodulates the received modulatedsignals, may perform further processing and provide the processedsignals corresponding to communicated message information to a givenconsumer, such as a main processor of an IoT device, as an example.

In an embodiment, the dynamic control of the center frequency of ADC 150₁ may be implemented using slow frequency hopping to switch betweendifferent channels. In a particular embodiment, this slow frequencyhopping may be implemented by configuring the band-pass ADC to operateat a given center frequency for a predetermined amount of time, e.g.,one millisecond. If a valid preamble is detected during thispredetermined period, the band-pass ADC may continue to operate at thiscenter frequency for as long as it takes to receive the message.Thereafter, the band-pass ADC is re-configured to operate at anothercenter frequency in a search for new messages. Such operation may occuriteratively based on configuration of a device in a particular meshnetwork. For example, if it is known a priori that a network includesdevices that only communicate on one or two of multiple possiblechannels, the band-pass ADC may be dynamically controlled to operate atcenter frequencies for only these one or two channels. And it isentirely possible that in a particular network, only devices are presentthat operate at a single one of these multiple channels, such that thecontrol of the pass-band for the band-pass ADC may be staticallycontrolled.

In some use cases, receiver 100 may be configured to operate in a lowpower mode in which only a single channel of interest is to be received.In such cases, ADC 150 ₁ itself may be placed into a low power or idlemode, and the single channel of interest may be digitized in ADC 150 ₀.To this end, controller 180 may cause ADC 150 ₁ to enter into this lowpower mode and further control a cutoff frequency of ADC 150 ₀ asappropriate for reception of this single channel of interest.

In an embodiment, ADCs 150 may be implemented as sigma delta convertershaving a desired resolution (e.g., between approximately 10 and 12bits). In a particular embodiment, these sigma delta converters may beimplemented with a modulator architecture having a conjugatearrangement, with two real channels, one for in-phase (I) signals andone for quadrature phase (Q) signals. Such conjugate architecture may beself-contained for ADC 150 ₀ and connected via variable cross-couplingfor ADC 150 ₁. The center frequency of ADC 150 ₁ may be changed bychanging the cross-coupling between the two real channels. The centerfrequency is linked to the integration capacitance and thetransconductance of the cross-coupling, which is linked by using unittransconductance elements. Understand while shown at this high level inthe embodiment of FIG. 1, many variations and alternatives are possible.

Referring now to FIG. 2, shown is a flow diagram of a method inaccordance with an embodiment. Method 200 is a method for configuring areceiver having a common front end signal processing path and multipleback end signal processing paths as described herein. In an embodiment,method 200 may be performed by hardware circuitry, firmware, softwareand/or combinations thereof. In a particular embodiment, method 200 maybe performed by a controller of the receiver, such as a microcontrollerunit (MCU) or other microcontroller included in or coupled to thereceiver. In any event, method 200 begins by configuring a frequencysynthesizer of the receiver to operate at a given local oscillatorfrequency (block 210). This LO frequency may be chosen based at least inpart on a channel of interest for a channel to be processed using alow-pass ADC. That is, the LO frequency may be set such that thedownconversion of the incoming RF spectrum leads to an IF frequency inwhich this channel of interest is located at a relatively lowintermediate frequency (e.g., less than 0.5 MHz). To configure thefrequency synthesizer, the microcontroller may send one or more controlsignals to the frequency synthesizer to cause it to generate a mixingsignal at this LO frequency.

Next control passes to block 220, where a first ADC may be configured tooperate at a low-pass frequency to capture this first channel ofinterest. As discussed above, in one example this first ADC may be sethaving a center frequency of 250 kHz and a bandwidth of 0.5 MHz. Next,at block 230, a second ADC may be configured to operate at a band-passfrequency to capture this second channel of interest. As discussedabove, in one example this second ADC may be set having a given one ofmultiple center frequencies (e.g., one of 1, 2, or 4 MHz) and abandwidth of 0.5 MHz.

At this point, the receiver is appropriately configured so that it canreceive and process signals of multiple channels of interestconcurrently. As such, at block 240 the receiver may operate asconfigured.

Because one or more ADCs or other band-pass filters may be dynamicallycontrolled to operate at different frequencies, as further shown in FIG.2 it may be determined at diamond 250 whether it is time to reconfigurethe second ADC (and optionally a low-pass filter of the common receiversignal processing path). As described above, in an embodiment suchreconfiguring may occur according to a slow frequency hopping technique.If it is determined that reconfiguration is appropriate, control passesnext to block 260 where the second ADC may be reconfigured. Morespecifically, the second ADC may be re-configured to operate at adifferent center frequency (and optionally a different bandwidth). Andoptionally, the low-pass filter also may be reconfigured to operate at adifferent cutoff frequency. Thereafter, continued operation of thereceiver with this new configuration may occur. Note that it is possiblefor the low-pass path to continue receiving and processing signals whilethe second path undergoes reconfiguration. Understand while shown atthis high level in the embodiment of FIG. 2, many variations andalternatives are possible.

Referring now to FIG. 3, shown is a flow diagram of a method inaccordance with another embodiment. More specifically, method 300 is amethod for concurrently processing signals of multiple paths in areceiver in accordance with an embodiment. As an example, method 300 maycorrespond to the operation of the configured receiver as shown at block240 in FIG. 2.

In an embodiment, method 300 may be performed by receiver components asdescribed herein. In an embodiment, method 300 may be performed byhardware circuitry, firmware, software and/or combinations thereof. Asillustrated, method 300 begins at block 310 by operating the frequencysynthesizer to output a mixing signal at a given LO frequency. Thismixing signal having the LO frequency is provided to a mixer, whichdownconverts the RF signal to an IF level using the mixing signal.

Thereafter at block 320 the ADCs may be controlled to operate at theirconfigured frequencies (e.g., having particular signed centerfrequencies and bandwidths). Additional configuration of the ADCs, suchas their resolution levels, power consumption and so forth also may beset. Note also that the gain of each ADC is also programmable with again set by an AGC subsystem.

With the receiver operating according to its configured parameters, nextat block 330 an incoming RF spectrum is received and downconverted to anintermediate frequency, using the mixer. Then the IF spectrum may besent to parallel back end signal processing paths including separateADCs, with one ADC configured as a low-pass ADC and the other configuredas a band-pass ADC. Of course additional parallel processing paths maybe present in a given embodiment. Note that additional signal processingof the IF spectrum may occur prior to being passed to the ADCs. In anycase, at block 350, IF signals are digitized in both ADCs to extractinformation of different channels of interest, if present. If so, atblocks 360 and 370, independent digital processing of the recovereddigitized signals may be performed. In one embodiment, a single DSP asimplemented within the same IC as the receiver may perform variousprocessing, including any additional filtering, decoding anddemodulation to extract any message information present in the digitizedsignals. Understand of course that such message content may be sent to agiven consumer, e.g., of an IoT device including the receiver. Althoughshown at this high level in the embodiment of FIG. 3, many variationsand alternatives are possible.

Referring now to FIGS. 4A and 4B, shown are illustrations of RF and IFfrequency spectrums in accordance with an embodiment. As illustratedfirst in FIG. 4A, an RF spectrum 400 includes multiple RF signals ofinterest, namely a first RF signal 410 at a first frequency f₁corresponding to a first channel of interest and a second RF signal 420at a second frequency f₂ corresponding to a second channel of interest.These incoming RF signals are mixed with an LO signal, namely LO signal415 at a LO frequency (fro) to downconvert them to lower secondfrequencies. As seen, first RF signal 410 is at a lower frequency thanLO signal 415 (namely separated from the LO frequency by a frequencydifference of Δf₁). Second RF signal 420 is at a higher frequency thanLO signal 415 (namely separated from the LO frequency by a frequencydifference of Δf₂). In embodiments, the LO frequency may be controlledsuch that it is at a frequency between the frequencies of the twochannels of interest.

Referring now to FIG. 4B, shown is an illustration of IF signalsgenerated using a complex mixer. In an IF spectrum 450, thecorresponding RF signals have been downconverted to IF signals. Morespecifically, each RF signal is downconverted into two IF signals atpositive and negative frequencies. As such, IF signals 460 _(n) and 460_(p) are corresponding negative and positive frequency IF signalsresulting from the downconversion of first RF signal 410. Asillustrated, IF signals 460 _(n,p) are at corresponding ±Δf₁ frequenciesfrom 0 Hz. Similarly, negative and positive second IF signals 470 _(n,p)are at corresponding IF frequencies of ±Δf₂ from 0 Hz. With embodimentsherein, a low-pass ADC may be configured to pass one of first IF signals460 and similarly, a band-pass ADC may be configured to pass one ofsecond IF signals 470. In an embodiment, the ADCs may be configured topass a positive or negative one of the different IF signals.

Embodiments may be used in many different types of receivers. Forpurposes of illustration, an example integrated circuit is described ata high level. As illustrated in FIG. 5, integrated circuit 500 is asystem in package (SiP), which may be an IoT device to provide a varietyof different functionality, including controller functionality, sensingfunctionality, actuator functionality or other automation or securityfunctions.

In the high level shown in FIG. 5, IC 500 includes a main processor 510,which may be implemented as a given central processing unit (CPU). Mainprocessor 510, which may perform the primary functions of the device, isin communication with memories including a non-volatile memory 515,e.g., a flash memory, and a volatile memory, e.g., a random accessmemory (RAM) 520. Additional functionality may be provided by a varietyof engines, including a dimmer engine 550, a keypad scanner 560, aninfrared (IR) controller 570, a light emitting diode (LED) controller575, an ADC 580, and a security engine 585, e.g., in accordance with agiven advanced encryption standard (AES) security protocol.

As further illustrated, to enable wireless communication, e.g., within agiven mesh network, a sub-gigahertz wireless transceiver 530 is present.In embodiments, wireless transceiver 530 may include a single front endreceiver signal processing path and multiple digitizers, e.g., low-passADC and at least one controllable band-pass ADC as described herein toenable multiple physically separated channels of interest to beconcurrently received and processed. This arrangement may be realizedwith minimal chip and power consumption requirements, owing to thecommon front end receiver path. As further shown, wireless transceiver530 couples to a modem 535 which may perform modulation and demodulationoperations to communicate corresponding signals with CPU 510 and othercomponents within IC 500. As further shown, a baseband controller 540 ispresent to control configuring of pass-bands for frequency hopping.Understand while shown at this high level in the embodiment of FIG. 5,many variations and alternatives are possible.

IoT devices including a receiver in accordance with embodiments may beincorporated in many different types of networking systems. Inparticular situations, IoT devices may be used in mesh networks such asa home area network (HAN) or other building or network arrangement.Referring now to FIG. 6, shown is a block diagram of mesh network 600 inaccordance with an embodiment. As shown in FIG. 6, a plurality ofdevices including IoT devices couple together via a mesh.

To enable communication from a controller 610 to a given device 660,e.g., a door lock, a two-way path may be realized via intermediatedevices, including devices 620 ₁-620 ₄. Additional mesh network devicesinclude devices 630 ₁-630 ₃, devices 640 ₁-640 ₂ and devices 650 ₁-650₂. With an arrangement as in FIG. 6, devices may operate in a low powermode where they may primarily operate in a sleep mode to reduce batteryconsumption, as many or all devices within mesh network 600 may bebattery-operated devices. To this end, embodiments may implement abeam-based wakeup technique in which, e.g., controller 610 issues a beamsignal that is received, e.g., by device 660. Upon receipt of this beamsignal intended for it, device 660 exits the low power state into anactive state to perform a given function, in response to a command fromcontroller 610.

With embodiments, during low power mode device 640 may be controlled tolisten for a single channel on which this beam communication occurs. Tothis end, device 640 may be configured such that its low-pass ADC isactive to listen for this beam signal while its band-pass ADC is placedin an idle, low power state. When detection of a beam signal intendedfor device 640 is detected, device 640 may cause its band-pass ADC to beplaced into an active mode to receive signals on one or more otherchannels of interest, namely main band signals via which it may receivecommand information, data information or so forth.

With embodiments herein, various devices in mesh network 600 maycommunicate with multiple other devices operating at differentfrequencies using selective frequency hopping as described herein. Inparticular examples, devices within mesh network 600 may operate atfrequencies between approximately 850 MHz and 930 MHz. To enable a givenreceiver to communicate with multiple such devices operating atdifferent frequencies, dynamic configuration of one or more low-passfilters, low-pass ADCs and band-pass ADCs may be performed to enable areceiver to dynamically and concurrently receive signals communicated inmultiple physically separate channels. Understand while shown at thishigh level in the embodiment of FIG. 6, many variations and alternativesare possible.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art will appreciate numerousmodifications and variations therefrom. It is intended that the appendedclaims cover all such modifications and variations as fall within thetrue spirit and scope of this present invention.

What is claimed is:
 1. An apparatus comprising: a front end circuit toreceive and process a radio frequency (RF) spectrum into a firstintermediate frequency (IF) signal having a first channel of interestand a second IF signal having a second channel of interest; a firstdigitizer to digitize the first IF signal to a first digitized signal,the first digitizer configured to operate as a low-passanalog-to-digital converter (ADC) that is statically controlled; asecond digitizer to digitize the second IF signal to a second digitizedsignal, the second digitizer configured to operate as a band-pass ADCthat is dynamically controlled; and a controller to dynamically controla center frequency for the second digitizer.
 2. The apparatus of claim1, wherein the controller is to dynamically control the center frequencyfor the second digitizer to perform frequency hopping for a plurality ofchannels of interest.
 3. The apparatus of claim 1, wherein thecontroller is to dynamically control the second digitizer to operate ateach of a plurality of center frequencies for a predetermined amount oftime.
 4. The apparatus of claim 3, wherein if a valid preamble isdetected during the predetermined amount of time that the seconddigitizer is in operation at a first center frequency, the controller isto cause the second digitizer to operate at the first center frequencyuntil a message has been received.
 5. The apparatus of claim 1, whereinthe apparatus is to concurrently receive and process the first channelof interest and the second channel of interest.
 6. The apparatus ofclaim 1, wherein the controller to dynamically control a bandwidth forthe second digitizer.
 7. The apparatus of claim 1, wherein thecontroller is: for a first time period, to configure the seconddigitizer to operate at a first center frequency to digitize and passthe second channel of interest; and for a second time period, toconfigure the second digitizer to operate at a second center frequencyto digitize and pass another one of a plurality of channels of interest.8. The apparatus of claim 7, further comprising a low-pass filtercoupled to the first and second digitizers, wherein the controller is toconfigure the low-pass filter to operate at plurality of cutofffrequencies, each of the plurality of cutoff frequencies associated witha corresponding center frequency for the second digitizer.
 9. Theapparatus of claim 1, wherein the controller is to cause the seconddigitizer to be powered off when the apparatus is in operation in a lowpower mode.
 10. The apparatus of claim 9, wherein the controller is tocause the second digitizer to be powered on in response to receipt of abeam signal during the low power mode, wherein the first digitizer isactive in the low power mode.
 11. The apparatus of claim 1, furthercomprising a digital processor to digitally process the first digitizedsignal and the second digitized signal.
 12. A method comprising:configuring, via a controller, a first analog-to-digital converter (ADC)of a receiver to operate at a fixed center frequency to capture a firstchannel of interest on which a beam communication occurs; controlling,via the controller, a second ADC of the receiver to be in a low powerstate; detecting, using at least in part the first ADC, a beam signal ofthe beam communication; and in response to detecting the beam signal,controlling the second ADC to be in an active state.
 13. The method ofclaim 12, further comprising, in the active state, configuring thesecond ADC to operate at a plurality of center frequencies to capture aplurality of channels of interest.
 14. The method of claim 13, furthercomprising: receiving and processing, in a common receiver signalprocessing path of the receiver, a radio frequency (RF) spectrum, toprovide an intermediate frequency (IF) spectrum from the common receiversignal processing path to the first ADC and the second ADC; in the firstADC, digitizing the first channel of interest into a first digitizedsignal and providing the first digitized signal to at least one digitalprocessor; and in the second ADC, digitizing the plurality of channelsof interest into a plurality of digitized signals and providing theplurality of digitized signals to the at least one digital processor.15. The method of claim 12, further comprising: configuring a low-passfilter to operate at a first cutoff frequency to enable a first one ofthe plurality of channels of interest to be passed; and re-configuringthe low-pass filter to operate at a second cutoff frequency to enable asecond one of the plurality of channels of interest to be passed.
 16. Asystem comprising: a common receiver signal processing path to receiveand process a radio frequency (RF) spectrum into a first intermediatefrequency (IF) signal having a first channel of interest to communicatea beam signal and a second IF signal having a second channel of interestcomprising main band signals; a first analog-to-digital converter (ADC)coupled to the common receiver signal processing path to digitize thefirst IF signal into a first digitized signal, the first ADC configuredto operate at a low-pass; a second ADC coupled to the common receiversignal processing path to digitize the second IF signal into a seconddigitized signal, the second ADC configured to operate at a controllableband-pass to perform frequency hopping for a plurality of channels ofinterest; and a controller coupled to the first ADC and the second ADC,the controller to cause the second ADC to be in a low power mode untilthe beam signal is detected, and to thereafter control the second ADC tobe in an active mode.
 17. The system of claim 16, wherein the controlleris to configure a local oscillator to generate a mixing signal having afrequency between a frequency of the first channel of interest and afrequency of the second channel of interest.
 18. The system of claim 16,wherein the controller is to dynamically control a center frequency forthe second ADC to perform the frequency hopping.
 19. The system of claim18, wherein the controller is to cause the second ADC to operate for afirst time period at a first center frequency to digitize and pass thesecond channel of interest and to operate for a second time period at asecond center frequency to digitize and pass a third channel ofinterest.
 20. The system of claim 16, wherein the controller is to causedynamically control a bandwidth of the second ADC.